Apparatus and Methods for Locating an Ostium of a Vessel
Apparatus and methods are provided for locating an ostium of a body lumen. In one embodiment, a delivery catheter or other tubular member includes a distal end sized for introduction into a body lumen, and one or more locator loops on the distal end. In one embodiment, the locator loop may include first and second ends fixed to the distal end, first and second resilient struts extending from the first and second ends, respectively, and a curved intermediate region extending between the first and second struts. The loop may be resiliently compressible to a contracted condition for delivery and resiliently expandable to an enlarged condition when deployed. The apparatus may include one or more balloons, stents, and the like on the distal end adjacent the locator loop.
This application claims benefit of provisional application Ser. No. 60/683,931, filed May 23, 2005, the entire disclosure of which is expressly incorporated by reference herein.
FIELD OF THE INVENTIONThe present invention relates generally to apparatus and methods for locating an ostium of a blood vessel or other body lumen, and, more particularly, to apparatus and methods for locating an ostium of a blood vessel or other body lumen to deliver a stent or other prosthesis into or adjacent the ostium.
BACKGROUNDTubular endoprosthesis or “stents” have been suggested for dilating or otherwise treating stenoses, occlusions, and/or other lesions within a patient's vasculature or other body lumens. For example, a self-expanding stent may be maintained on a catheter in a contracted condition, e.g., by an overlying sheath or other constraint, and delivered into a target location, e.g., a stenosis within a blood vessel or other body lumen. When the stent is positioned at the target location, the constraint may be removed, whereupon the stent may automatically expand to dilate or otherwise line the vessel at the target location. Alternatively, a balloon-expandable stent may be carried on a catheter, e.g., crimped or otherwise secured over a balloon, in a contracted condition. When the stent is positioned at the target location, the balloon may be inflated to expand the stent and dilate the vessel.
Sometimes, a stenosis or other lesion may occur at an ostium or bifurcation, i.e., where a branch vessel extends from a main vessel. For example, such a lesion may form within a coronary artery immediately adjacent the aortic root. U.S. Pat. No. 5,749,890 to Shaknovich discloses a stent delivery assembly for placing a stent in an ostial lesion. U.S. Pat. No. 5,632,762 to Myler discloses a tapered balloon on a catheter for positioning a stent within an ostium. U.S. Pat. No. 5,607,444 to Lam discloses an expandable ostial stent including a tubular body and a deformable flaring portion. Published application US 2002/0077691 to Nachtigall discloses a delivery system that includes a sheath for holding a stent in a compressed state during delivery and a retainer that holds a deployable stop in an undeployed position while the delivery system is advanced to a desired location.
Accordingly, apparatus and methods for locating an ostium and/or for delivering a stent within an ostium would be useful.
SUMMARY OF THE INVENTIONThe present invention is directed to apparatus and methods for locating a branch body lumen extending from a main body lumen, and, more particularly, to apparatus and methods for locating an ostium or bifurcation of a blood vessel or other body lumen, e.g., for delivering a stent or other prosthesis within or adjacent the ostium and/or for accessing the blood vessel.
In accordance with one embodiment, an apparatus is provided that includes a tubular member including proximal and distal ends, and a lumen extending between the proximal and distal ends, an elongate member including a distal portion disposed within the lumen such that the distal portion may be advanced beyond the tubular member distal end, an expandable locator on the distal portion. In one embodiment, the locator includes a loop including first and second ends fixed to the distal portion, first and second resilient struts extending from the first and second ends, respectively, and a curved intermediate region extending between the first and second struts. The loop may be resiliently compressible to a contracted condition when the distal portion is disposed within the lumen and resiliently expandable to an enlarged condition when the distal portion is advanced beyond the tubular member distal end.
In an exemplary embodiment, the loop may substantially define a plane in the enlarged condition and/or the plane may define an acute angle with a longitudinal axis of the tubular member. In another embodiment, the loop may be twisted asymmetrically relative to a longitudinal axis of the tubular member in the enlarged condition.
In alternative embodiments, only a single loop or a plurality of expandable loops may be provided on the distal portion of the tubular member. If a plurality of expandable loops are provided, the loops may be disposed symmetrically or asymmetrically around a circumference of the tubular member. In one embodiment, the plurality of expandable loops may include curved intermediate regions that generally define a portion of an ellipse surrounding the distal portion.
In accordance with another embodiment, an apparatus is provided for locating an ostium of a body lumen. Generally, the apparatus includes an elongate member including a distal portion that may advanced through a guide catheter or other tubular member, and a plurality of expandable loops on the distal portion. Each loop may include first and second resilient struts extending from the distal portion, and a curved intermediate region extending between the first and second struts. In addition or alternatively, each loop may be resiliently compressible to a contracted condition when the distal portion is disposed within the tubular member and resiliently expandable to an enlarged condition when the distal portion is advanced from the tubular member.
In one embodiment, the loops may be disposed around the distal portion such that the intermediate regions define at least a portion of an ellipse surrounding the distal portion when the loops are in the enlarged condition. In addition or alternatively, the struts may be resiliently deflectable when the loops are expanded to the enlarged condition to provide tactile feedback when one or more of the intermediate regions contact an ostium.
Optionally, a tubular prosthesis may be provided on the distal portion, e.g., adjacent the loops such that the apparatus may be used to position the prosthesis within an ostium.
In accordance with still another embodiment, an apparatus is provided for locating an ostium of a body lumen that includes a tubular member including a proximal end, a distal end sized for introduction into a body lumen, a lumen extending between the proximal and distal ends, and a distal portion. One or more locator elements may be disposed asymmetrically on the distal portion, each locator element including a first end fixed to the distal portion and a second end free from the distal portion. Each locator element may be resiliently compressible to a contracted condition when the distal portion is disposed within a lumen of a delivery device, and each locator element being resiliently expandable to an enlarged condition when fully deployed from the delivery device.
Optionally, a stent or other prosthesis may be disposed on the distal portion.
In accordance with yet another embodiment, an apparatus is provided for locating an ostium of a body lumen that includes a tubular member including a proximal end, a distal end sized for introduction into a body lumen, a lumen extending between the proximal and distal ends, and a distal portion, and a locator loop on the distal portion. The locator loop may be resiliently compressible to a contracted condition when the distal portion is disposed within a lumen of a delivery device and/or resiliently expandable to an enlarged condition when fully deployed from the delivery device.
In one embodiment, the locator loop may include a loop that substantially surrounds the distal portion of the tubular member in the enlarged condition, and a plurality of struts extending between the loop and the distal portion for attaching the locator loop to the tubular member. Optionally, the struts may include an inner portion closer to the tubular member and an outer portion closer to the loop, the inner portion being more rigid than the outer portion. In addition or alternatively, one or more supports may extend between adjacent struts at intermediate regions of the struts.
In another embodiment, the locator loop may include a base attached to the distal portion of the tubular member, the struts extending from the base. Optionally, at least the base and the struts may be formed from a unitary tubular body. Optionally, the loop may also be formed from the unitary tubular body, or the loop may be formed from one or more wires attached to the unitary tubular body.
In accordance with still another embodiment, a method is provided for delivering a stent within an ostium communicating from a main body lumen to a branch body lumen. A distal end of a delivery catheter may be advanced into the main body lumen, the distal end including one or more locator elements constrained in a contracted condition. The one or more locator elements may be released within the main body lumen and directed against a wall of the ostium, and a procedure may be performed at or within the ostium based upon the position of the one or more locator elements in the enlarged condition, e.g., a stent may be delivered into the ostium.
In one embodiment, the one or more locator elements may assume an asymmetrical orientation upon being released and/or may cause the distal end of the delivery catheter to rotate about its longitudinal axis when the locator elements are released.
In addition or alternatively, the one or more locator elements may provide tactile feedback resisting further advancement when the one or more locator elements contact the main body lumen wall adjacent the ostium.
In accordance with still another embodiment, a method is provided for delivering a stent within an ostium communicating from a main body lumen to a branch body lumen. A distal end of a delivery catheter may be advanced into the main body lumen, and one or more locator elements on the distal end may be released within the main body lumen, the one or more locator elements resiliently expanding to substantially surround the distal end. The one or more locator elements may be directed against a wall of the ostium, thereby causing one or more struts supporting the one or more locator elements to bend away from the ostium. A procedure, e.g., stent delivery, may then be performed at or within the ostium based upon the position of the one or more locator elements in the enlarged condition.
Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGSThe drawings illustrate exemplary embodiments of the invention, in which:
Turning to the drawings,
In addition, the apparatus 10 may include a guide catheter 60 including a proximal end 62, a distal end 64, and a lumen 66 extending therebetween. The distal end 64 may be sized and/or shaped to facilitate advancement into a patient's vasculature or other body lumen, as described further below. The lumen 66 may have sufficient size for receiving the distal end 16 of the delivery catheter 12 therethrough, e.g., with the locator loop 50 in a contracted condition, also as explained further below. Optionally, the distal end 64 of the guide catheter 60 may be biased to a predetermined shape, e.g., a “J” shape, which may facilitate positioning the guide catheter 60 within or adjacent an ostium. The guide catheter 60 may be constructed from substantially flexible and/or floppy materials, e.g., plastic having a braid or other reinforcement (not shown) that sufficiently supports the guide catheter 60 to prevent kinking or buckling, while allowing the guide catheter 60 to be directed easily through tortuous anatomy. Optionally, the apparatus 10 may include other components to provide a system or kit for delivering the stent 40, e.g., a sheath that may be advanced over and/or retracted from the distal end 16 of the delivery catheter 12, one or more syringes or other sources of inflation media and/or vacuum, tubing, and/or one or more guidewires (all not shown).
With continued reference to
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In the embodiment shown in
In addition, the delivery catheter 12 may include one or more inflation lumens that extend from respective side port(s) 32b in the handle 30 through the delivery catheter 12 to openings (not shown) that communicate with an interior of a respective balloon 22. The side port(s) 32b on the handle 30 may include connectors, e.g., a luer lock connector (not shown), one or more seals (also not shown), and the like. A source of inflation media and/or vacuum, e.g., a syringe filled with saline (not shown), may be connected to the side port(s) 32b, e.g., via tubing (also not shown), for expanding and/or collapsing the balloon 22.
As shown in
The balloon (or balloons, not shown) 22 may be bonded or otherwise secured to the distal end 16 of the delivery catheter 12. For example, ends of the balloon 22 may be attached to the distal end 16 using one or more of bonding with an adhesive, sonic welding, an annular collar or sleeve, and the like. The balloon 22 may be expandable from a contracted condition (not shown, see, e.g.,
The balloon 22 may be formed from substantially inelastic material, e.g., PET, nylon, or PEBAX, such that the balloon 22 expands to a predetermined size in its enlarged condition once sufficient fluid is introduced into the interior of the balloon 22. Alternatively, the balloon 22 may be formed from substantially elastic material, e.g., silicone, polyurethane, or polyethylene, such that the balloon 22 may be expanded to a variety of sizes depending upon the volume and/or pressure of fluid within the interior.
The stent 40 may be formed from a variety of materials that may be plastically deformed to allow expansion of the stent 40. For example, the stent 40 may be formed from metal, such as stainless steel, tantalum, MP35N, Niobium, Nitinol, and L605, plastic, or composite materials. In particular, the materials of the stent 40 may be plastically deformed under the pressures experienced when the balloon 22 is expanded such that all or one or more portions of the stent 40 are deformed beyond their elastic limit. Thus, when the balloon 22 is subsequently collapsed, the stent 40 may maintain its expanded configuration with minimal recoil. For example, the stent 40 material may resist collapsing back towards its reduced configuration if the tissue surrounding the body lumen attempts to constrict or otherwise return to its occluded shape.
Alternatively, at least a portion of the stent 40 may be self-expanding. For example, the stent 40 may be biased to expand at least partially outwardly yet may be constrained over the balloon 22 in a contracted condition to facilitate delivery, e.g., using a sheath, filament, and the like (not shown). In this alternative, the stent 40 may be formed from Nitinol or other shape memory or superelastic materials. Optionally, the resistance of the stent 40 to expansion may be varied along its length. This performance of the stent 40 may be based upon mechanical properties of the material, e.g., which may involve heat treating one or more portions of the stent 40 differently than other portions. In addition or alternatively, the structure of the stent 40 may be varied, e.g., by providing struts, fibers, or other components in different portions having different widths, thicknesses, geometry, and the like.
The stent 40 may be a generally tubular structure, e.g., including openings in a tubular wall that facilitate expansion of the stent 40 and/or allow tissue ingrowth. For example, the stent may be an elongate tube that has slots or other openings formed in the tube wall, e.g., by laser cutting, mechanical cutting, chemical etching, machining, and the like. Alternatively, the stent 40 may be a braided or other structure, e.g., formed from one or wires or other filaments braided or otherwise wound in a desired manner. Additional possible stent structures may include helical coil wires or sheets. If desired, one or more portions of the stent 40 may include a membrane, film, or coating (not shown), e.g., to create a nonporous, partially porous, or porous surface between cells of the stent 40 and/or to carry one or more therapeutic compounds. Additional information on stents that may be delivered using the catheter 12 may be found in co-pending application Ser. No. 60/683,920, filed May 23, 2005, 60/710,521, filed Aug. 22, 2005, 60/731,568, filed Oct. 28, 2005, 60/757,600, filed Jan. 9, 2006, 60/743,880, filed Mar. 28, 2006, and 60/745,177, filed Apr. 19, 2006. The entire disclosures of these references are expressly incorporated by reference herein.
With additional reference to
The locator loop 50 may be formed from an elastic or superelastic material, e.g., metal such as Nitinol, stainless steel, and the like, plastic, and/or composite materials (e.g., a metal wire core covered with a plastic coating). The locator loop 50 is generally resiliently compressible to a contracted condition, and biased to expand to an enlarged condition, such as that shown in
For example, the locator loop 50 may be compressed against the distal end 16 of the delivery catheter 12 and constrained in the contracted condition, e.g., when the distal end 16 of the delivery catheter 12 is loaded into the lumen 66 of the guide catheter 60. In this condition, the struts 54 may extend substantially axially along the distal end 16 and the intermediate region 56 may be partially straightened, twisted, or otherwise compressed towards the surface of the distal end 16. Alternatively, a sheath (not shown) may be provided that extends over the distal end 16 of the delivery catheter 12 to constrain the locator loop 50 (and/or cover the stent 40 and balloon 22). When the distal end 16 of the delivery catheter 12 is advanced beyond the distal end 64 of the guide catheter 60 (or the overlying sheath is retracted), the locator loop 50 may resiliently expand to the enlarged condition.
The ends 52 of the locator loop 50 may be attached or otherwise secured to the distal end 16 of the delivery catheter 12. For example, an adhesive, sonic welding, fusing, and the like may be used to bond the ends 52 to the surface of the distal end 16. In addition or alternatively, a band of material, e.g., a heat shrink tube or other band of plastic, metal, wire, and the like, may be wrapped or otherwise extend around the ends 52 of the locator loop 50. In addition or alternatively, the ends 52 of the locator loop 50 may be at least partially embedded into the delivery catheter 12, e.g., into slots or holes partially or completely penetrating the wall of the delivery catheter 12. In yet another alternative, the ends 52 may be part of an annular band that may crimped or otherwise secured around the delivery catheter 12, e.g., in addition to or instead of the other attachment methods described above.
In the embodiment shown in
The struts 54 and/or intermediate region 56 may also be shaped such that the intermediate region 56 extends transversely relative to the longitudinal axis 20 of the catheter 12. For example, the struts 54 may be curved or otherwise transition from an axial direction to a transverse direction. As shown, the ends 52 may extend substantially axially, while the intermediate region 56 extends substantially perpendicular to the longitudinal axis 20. In alternative embodiments, such as those described elsewhere herein, the intermediate region 56 and/or other portions of the locator loop 50 may extend laterally relative to the longitudinal axis 20, e.g., defining an acute or oblique angle with the longitudinal axis 20.
The locator loop 50 may have sufficient strength (e.g., column strength and/or bending resistance) to be self-supporting, yet be at partially deflectable, e.g., to provide tactile feedback to a user, as explained further below. For example, one or more portions of the locator loop 50, e.g., the struts 54 and/or intermediate region 56, may bend or flex when the locator loop 50 contacts and is pushed against a surface (e.g., a wall of a body lumen adjacent an ostium). The initial contact may provide a first tactile feedback, and thereafter resist further bending or flexing to provide a second or additional tactile feedback, as described further elsewhere herein.
Turning to
An occlusion or other lesion 96 may exist at and/or adjacent to the ostium 90, e.g., extending at least partially into the branch 94. The lesion 96 may include atherosclerotic plaque or other material that partially or completely occludes blood or other fluid flow between the trunk 92 and the branch 94.
Initially, as shown in
After the guidewire 98 is directed into the branch 94 beyond the lesion 96, it may be desirable to at least partially dilate the lesion 96. For example, an angioplasty catheter (not shown) may be advanced through the guide catheter 60 and/or over the guidewire 98 into and through the lesion 96, whereupon a balloon or other element on the catheter may be expanded to at least partially dilate the lesion 96. If desired, other procedures may also be performed at the lesion 96, e.g., to soften, remove, or otherwise treat plaque or other material forming the lesion 96, before the stent 40 is implanted. After completing any such procedures, instruments advanced over the guidewire 98 may be removed.
As shown in
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For example, the relative location of the locator loop 50 to the stent 40 on the distal end 16 of the delivery catheter 12 may be predetermined such that the position where further distal movement is impeded by the locator loop 50 corresponds to the optimum distance into the ostium 90 and/or branch 94 for deploying the stent 40. Optionally, one or more radiopaque markers (not shown) may be provided, e.g., on one or both ends of the stent 40, on the catheter 12 or balloon 22 under one or both ends of the stent 40, and/or on the locator loop 50. In one embodiment, the locator loop 50 may be made radiopaque through the incorporation of radiopaque materials in its construction, either as an integral part of the loop wire, or as a structure attached to the loop wire. Contrast may be delivered, e.g., via the delivery catheter 12 or through the guide catheter 60 (e.g., after advancing the guide catheter 60 until the distal end 64 contacts the ostium 90), to facilitate identifying the position of the stent 40 relative to the ostium 90 under fluoroscopy or other external imaging.
Turning to
In a further alternative, the delivery catheter 12 may include multiple balloons (not shown) under the stent 40 that may be used to expand portions of the stent 40 sequentially, as described in application Serial No. 11/136,266 or the other applications incorporated by reference above. For example, a proximal balloon (not shown) may be inflated to expand a proximal portion of the stent 40, e.g., into a flared configuration, adjacent the locator loop 50. The delivery catheter 12 may be advanced distally, e.g., until the flared portion conforms or otherwise contacts the wall of the trunk 92 surrounding the ostium 90. Once the flared portion is seated, another balloon may be inflated to expand a distal portion of the stent 40 within the lesion 96 and/or branch 94.
Turning to
As the distal end 16 of the delivery catheter 12 is withdrawn into the guide catheter 60, the locator loop 50 may contact the distal end 64 of the guide catheter 60 and be resiliently compressed as the delivery catheter 12 is pulled into the lumen 66. For example, the locator loop 50 may be elongated, narrowed, and/or otherwise directed inwardly towards the surface of the distal end 16 of the delivery catheter 12 as the locator loop 50 is drawn into the lumen 66 of the guide catheter 60. If the struts 54 of the locator loop 50 are rounded or are inclined distally and/or transversely, they may facilitate pulling the locator loop 50 into the guide catheter 60.
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In a further alternative, shown in
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For example, turning to
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Optionally, as shown in
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In an alternative embodiment, shown in
In yet another alternative embodiment, shown in
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As shown in
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In one embodiment, the locator loop 150 may be formed from multiple segments of wire, with each segment defining a first end, a first strut, a curved region to a second strut, and a second end. Thus, in the embodiment shown in
In another embodiment, the locator loop 150 may be cut or otherwise formed from a single section of tubing. In this embodiment, the struts 154 may include single spokes (rather than adjacent struts) offset about the longitudinal axis 120, and curved regions 156 extending between the spokes 154. Thus, the locator loop 150 may be a unitary frame including a circular or elliptical portion defined by the curved regions 156, and a plurality of spokes that couple the locator loop 150 to the delivery catheter 112.
The locator loop 150 may be formed by laser cutting, mechanically cutting, etching, or otherwise removing material from a tube to create the frame. Exemplary materials for the locator loop 150 include elastic or superelastic materials, such as Nitinol (NiTi), stainless steel, a polymer or other plastic, or other materials described elsewhere herein. Optionally, the material of the locator loop 150 may be heat treated, e.g., to bias the frame to adopt the enlarged condition shown in
During use, the distal end 116 of the delivery catheter 112 may be loaded into a guide catheter (not shown) with the locator loop 150 constrained in a contracted condition using an introducer device (not shown). For example, after manufacturing or any time before use, the locator loop 150 may be compressed and placed within a tubular member or other introducer device that is small enough to be received in the proximal end of the guide catheter. Once the distal end 116 of the delivery catheter 112 and the locator loop 150 are positioned in the guide catheter, the introducer device may be removed, and the delivery catheter 112 advanced through the guide catheter, similar to the methods described above.
When the distal end 116 of the delivery catheter 112 is deployed from the guide catheter, the locator loop 150 may resiliently spring open and assume the enlarged condition shown in
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As best seen in
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The distal end 116′ of the delivery catheter 116′ may be advanced over the guidewire 98 into the ostium 90, e.g., until the balloon 122′ (and stent 40 carried thereon, not shown for clarity) is disposed adjacent the lesion 96 and/or within the branch 94. As shown in
One advantage of the locator loop 150′ is shown in
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With additional reference to
An intermediate portion of the tube 259 may be formed into the struts 254, which extend generally axially when cut from the tube 259. Each strut 254 may include an inner portion 254b coupled to the collar 252 and an outer portion 254a coupled to the outer loop portions 256. The inner portion 254b may have a wider width than the outer portion 254a and/or may have a greater thickness (not shown) such that the inner portion 254b has a higher resistance to bending than the outer portion 254a. Stated differently, the inner portion 254b may provide a relatively stiff spoke portion, while the outer portion 254a provides a relatively flexible spoke portion. When a bending moment is applied to the struts 254, e.g., when the locator loop 250 is directed against an ostium, as described above, the struts 254 may preferentially bend at the transition between the inner and outer portions 254b, 254a. Thus, the locator loop 250 may respond and provide tactile feedback similar to the embodiments described above.
The outer loop portions 256 may be formed from the end of the tube 259 opposite the collar 252. The outer loop portions 256 may be formed as a plurality of serpentine elements that extend around a circumference of the tube between adjacent struts 254. As shown, the outer loop portions 256 include a pair of straight sections 256a extending from adjacent struts 254 and a loop 256b extending between the straight sections 256a. Alternatively, if desired, multiple loops (not shown) may be provided between adjacent struts to provide outer loop portions 256 that expand in a desired manner.
Once the tube 259 is cut, e.g., into the pattern shown in
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Optionally, the wires 355 may be formed from drawn and filled tubes (“DFTs”), which may be a composite of a Nitinol outer tubular wire and a core of radiopaque material (e.g., gold, platinum, iridium, and the like). DFT wire may provide radiopacity without adding bulky elements to the locator loop.
There may be several advantages of providing the outer loop portions and/or outer portions 354a of the struts from a wire structure. For example, a wire may have a smoother, more uniform profile along its length, which may allow higher strength and/or minimal post-processing (i.e., electro-polishing, sandblasting, etc.). In addition, a wire may have a microstructure where the metal grains are oriented along the length of the wire. In contrast, cutting portions of the locator loop from a tube, e.g., the outer loop portions, the tube may be cut at angles that are not parallel to the grain structure, which may result in grain orientation that is irregular and/or may weaken the resulting locator loop. In addition, loops cut from a tube require the loops to be folded or bent, which may increase localized stresses, which may result in failure or other damage to the locator loop during use.
However, laser cut tubing may allow the collar to have a relatively small profile. Alternatively, a separate tube or other structure may be provided as a base to which the struts may be attached, but such a structure may be constructed less accurately, as compared to a laser cut collar. For example, in an alternative embodiment, a section of heat shrink tubing may be used to secured struts to the underlying catheter, although the heat shrink tubing may have less strength than a metal or other laser cut collar. Further, laser cut tubing may provide increased flexibility, i.e., allowing the various components, struts, collar, and loop portions, to be changed to meet desired mechanical and/or other performance criteria.
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During use, the delivery catheter 512 may be introduced into a trunk adjacent a branch with the locator arms 552 in the contracted condition shown in
Once the stent 40 is expanded and/or otherwise deployed, the balloon 522 may be deflated, and the distal end 516 of the delivery catheter 512 withdrawn into a guide catheter or other sheath (not shown). The balloon 556 may be deflated, whereupon the locator arms 552 may resiliently resume the contracted condition, allowing the locator arms 552 to be withdrawn into the guide catheter. Alternatively or in addition, the locator arms 552 may be compressed towards the contracted condition when the distal end 516 of the delivery catheter 512 is withdrawn into the guide catheter, similar to the other embodiments described herein.
For example,
Alternatively, as shown in
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It will be appreciated that elements or components shown with any embodiment herein are exemplary for the specific embodiment and may be used on or in combination with other embodiments disclosed herein.
While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope of the appended claims.
Claims
1. An apparatus for locating an ostium of a body lumen, comprising:
- a tubular member comprising a proximal end, a distal end sized for introduction into a body lumen, and a lumen extending between the proximal and distal ends;
- an elongate member comprising a distal portion disposed within the lumen such that the distal portion may be advanced beyond the tubular member distal end; and
- an expandable loop on the distal portion, the loop comprising first and second ends fixed to the distal portion, first and second resilient struts extending from the first and second ends, respectively, and a curved intermediate region extending between the first and second struts, the loop being resiliently compressible to a contracted condition when the distal portion is disposed within the lumen and resiliently expandable to an enlarged condition when the distal portion is advanced beyond the tubular member distal end.
2. The apparatus of claim 1, wherein the intermediate region defines an arcuate shape when the loop expands to the enlarged condition.
3. The apparatus of claim 2, wherein the arcuate shape defines a portion of an ellipse surrounding the distal portion.
4. The apparatus of claim 1, wherein the first and second struts extend transversely from the distal portion when the loop expands to the enlarged condition.
5. The apparatus of claim 4, wherein the first and second struts extend distally from the distal portion when the loop expands to the enlarged condition.
6. The apparatus of claim 5, further comprising a tubular prosthesis on the distal portion adjacent the first and second ends, the first and second struts extending over a portion of the prosthesis when the loops expands to the enlarged condition.
7. The apparatus of claim 1, wherein the loop substantially defines a plane in the enlarged condition, the plane defining an acute angle with a longitudinal axis of the tubular member.
8. The apparatus of claim 7, wherein the loop comprises an outer tip disposed away from the first and second ends, the outer tip extending out of the plane.
9. The apparatus of claim 1, wherein only a single loop is provided on the distal portion of the tubular member.
10. The apparatus of claim 1, wherein the expandable loop comprises a plurality of expandable loops.
11. The apparatus of claim 10, wherein the plurality of expandable loops are disposed asymmetrically around a circumference of the tubular member.
12. The apparatus of claim 11, wherein the plurality of expandable loops comprises curved intermediate regions that generally define a portion of an ellipse surrounding the distal portion.
13. The apparatus of claim 1, wherein the loop substantially defines a “D” shape in the enlarged condition.
14. The apparatus of claim 1, wherein the loop generally defines a curved shape in the enlarged condition define a surface extending transversely relative to a longitudinal axis of the tubular member.
15. The apparatus of claim 1, wherein the loop comprises a plurality of wires wound around one another and extending between the first and second ends.
16. The apparatus of claim 1, wherein the loop comprises a curved banana-peel shape in the enlarged condition.
17. The apparatus of claim 1, wherein the loop is twisted asymmetrically relative to a longitudinal axis of the tubular member in the enlarged condition.
18. The apparatus of claim 17, wherein the loop generally defines a plane in the enlarged condition, and wherein a normal axis extending from the plane does not extend substantially parallel to the longitudinal axis of the tubular member.
19. The apparatus of claim 17, wherein the first strut extends more axially than the second strut in the enlarged condition.
20. The apparatus of claim 17, wherein the first strut has a length that is shorter than the second strut.
21. The apparatus of claim 1, wherein the struts are resiliently deflectable when the loops expands to the enlarged condition to provide tactile feedback when the intermediate region contacts an ostium.
22. The apparatus of claim 1, wherein the struts extend axially when the loop is in the contracted condition.
23. The apparatus of claim 22, wherein the intermediate region defines a serpentine shape when the loop is in the contracted condition.
24. The apparatus of claim 1, wherein the loop comprises at least one of a wireform and a slotted tube.
25. An apparatus for locating an ostium of a body lumen, comprising:
- a tubular member comprising a proximal end, a distal end sized for introduction into a body lumen, and a lumen extending between the proximal and distal ends;
- an elongate member comprising a distal portion disposed within the lumen such that the distal portion may be advanced beyond the tubular member distal end; and
- a plurality of expandable loops on the distal portion, each loop comprising first and second resilient struts extending from the distal portion, and a curved intermediate region extending between the first and second struts, each loop being resiliently compressible to a contracted condition when the distal portion is disposed within the lumen and resiliently expandable to an enlarged condition when the distal portion is advanced beyond the tubular member distal end, the loops being disposed around the distal portion such that the intermediate regions define at least a portion of an ellipse surrounding the distal portion when the loops are in the enlarged condition.
26. The apparatus of claim 25, wherein the first and second struts extend transversely from the distal portion when the loops expand to the enlarged condition.
27. The apparatus of claim 26, wherein the first and second struts extend distally from the distal portion when the loops expand to the enlarged condition.
28. The apparatus of claim 27, further comprising a tubular prosthesis on the distal portion adjacent the loops such that the first and second struts extend over a portion of the prosthesis when the loops expand to the enlarged condition.
29. The apparatus of claim 25, wherein the struts are resiliently deflectable when the loops are expanded to the enlarged condition to provide tactile feedback when one or more of the intermediate regions contact an ostium.
30. The apparatus of claim 25, wherein the struts extend axially when the loops are in the contracted condition.
31. The apparatus of claim 30, wherein the intermediate regions define a serpentine shape when the loops are in the contracted condition.
32. The apparatus of claim 25, wherein the loops comprise at least one of a wireform and a slotted tube.
33. An apparatus for locating an ostium of a body lumen, comprising:
- a tubular member comprising a proximal end, a distal end sized for introduction into a body lumen, a lumen extending between the proximal and distal ends, and a distal portion;
- one or more locator elements disposed asymmetrically on the distal portion, each locator element comprising a first end fixed to the distal portion and a second end free from the distal portion, each locator element being resiliently compressible to a contracted condition when the distal portion is disposed within a lumen of a delivery device, each locator element being resiliently expandable to an enlarged condition when fully deployed from the delivery device; and
- a stent on the distal portion.
34. The apparatus of claim 33, wherein only a single locator element is disposed on the distal portion, the locator element extending transversely from the distal portion in the enlarged condition.
35. The apparatus of claim 33, wherein the one or more locator elements comprise a plurality of locator elements, the locator elements disposed adjacent one another around only a portion of a circumference of the tubular member.
36. The apparatus of claim 35, wherein the plurality of locator elements comprise outer curved portions that together define only a portion of an ellipse extending around a portion of the distal portion.
37. The apparatus of claim 33, wherein the one or more locator elements comprise one or more wire loops.
38. An apparatus for locating an ostium of a body lumen, comprising:
- a tubular member comprising a proximal end, a distal end sized for introduction into a body lumen, a lumen extending between the proximal and distal ends, and a distal portion; and
- a locator loop on the distal portion that is resiliently compressible to a contracted condition when the distal portion is disposed within a lumen of a delivery device and is resiliently expandable to an enlarged condition when fully deployed from the delivery device, the locator loop comprising a loop that substantially surrounds the distal portion of the tubular member in the enlarged condition, and a plurality of struts extending between the loop and the distal portion for attaching the locator loop to the tubular member.
39. The apparatus of claim 38, wherein the struts comprise an inner portion closer to the tubular member and an outer portion closer to the loop, the inner portion being more rigid than the outer portion.
40. The apparatus of claim 39, wherein the inner portion has at least one of a width and a thickness that is greater than the outer portion.
41. The apparatus of claim 38, further comprising one or more supports extending between adjacent struts at intermediate regions of the struts.
42. The apparatus of claim 38, wherein the locator loop comprises a base attached to the distal portion of the tubular member, the struts extending from the base.
43. The apparatus of claim 42, wherein the base and the struts are formed from a unitary tubular body.
44. The apparatus of claim 43, wherein the loop is formed from the unitary tubular body.
45. The apparatus of claim 43, wherein the loop defines a serpentine shape in the contracted condition, the loop being heat treated to expand resiliently to the enlarged condition from the serpentine shape when deployed from the delivery device.
46. The apparatus of claim 43, wherein the loop is formed from one or more wires attached to the unitary tubular body.
47. A method for delivering a stent within an ostium communicating from a main body lumen to a branch body lumen, comprising:
- advancing a distal end of a delivery catheter into the main body lumen, the distal end comprising one or more locator elements constrained in a contracted condition;
- releasing the one or more locator elements within the main body lumen, the one or more locator elements resiliently expanding asymmetrically;
- directing the one or more locator elements against a wall of the ostium, the one or more locator elements causing the distal end of the delivery catheter to rotate about its longitudinal axis; and
- performing a procedure at or within the ostium based upon the position of the one or more locator elements in the enlarged condition.
48. The method of claim 47, further comprising advancing the distal end after the one or more locator elements expand towards the enlarged condition, the one or more locator elements providing tactile feedback resisting further advancement when the one or more locator elements contact the main body lumen wall adjacent the ostium.
49. The method of claim 47, wherein the procedure comprises delivering a stent within at least one of the ostium and the branch.
50. A method for delivering a stent within an ostium communicating from a main body lumen to a branch body lumen, comprising:
- advancing a distal end of a delivery catheter into the main body lumen, the distal end comprising one or more locator elements constrained in a contracted condition;
- releasing the one or more locator elements within the main body lumen, the one or more locator elements resiliently expanding to substantially surround the distal end;
- directing the one or more locator elements against a wall of the ostium, thereby causing one or more struts supporting the one or more locator elements to bend away from the ostium; and
- performing a procedure at or within the ostium based upon the position of the one or more locator elements in the enlarged condition.
Type: Application
Filed: May 23, 2006
Publication Date: Jan 25, 2007
Inventors: Jeff Krolik (Campbell, CA), Elliot Kim (Santa Clara, CA), James Dreher (Santa Monica, CA)
Application Number: 11/419,997
International Classification: A61F 2/06 (20060101);